livewell drain operation

Hi all, just picked up an `89 smokercraft resorter that needs alot of work. It has a nice big livewell that i understand how it fills up and theres an overflow that flows out the side of the boat but, how does it drain. Theres no bottom drain plug in the well, So does it just flow back through the pump when its not on? And if so does it constantly empty so i have to leave the pump on all the time? I`ve never had a boat with a livewell before so its all new to me. The Previous owner had started to gut the interior along with removing the livewell but lost interest and I got it this way. Thanks